Improvement in pistons for steam-cylinders



UNITED STATES PATENT Orrron.

SAMUEL D. KEENE, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR OF ONE- HALF TO JAMES R. WHEELER, OF SAME PLACE.

IMPROVEMENT IN PISTONS FOR STEAM-CYLINDERS.

Specification forming part of Letters Patent No. 152,905, dated July 14, 1874; application tiled April 23, 1873.

To alt whom it may concern:

Be it known that I, SAMUEL DAVIS KEENE, of Providence, in the county of Providence, State of Rhode Island, have invented certain new and useful Improvements in Pistons for Steam-Cylinders, of which the following is a sp ccilieation:

This invention consists of a fixed ring perforated for the passage of steam, in combination with free-cut rings, when said rings are made free both from the disks and from the fixed ring, as hereinafter more fully described and claimed.

Figure 1 is a plan of the piston with the upper disk removed. Fig. 2 is a cross-section of my invention. Fig. 3 shows in detail one of the double-headed valves, a part of each of the disks, and the adjustable seat. Fig. 4 is an end view of the double-headed valve.

The general features of m y invention are fully set forth in the specification of the patent to Matthew B. Mason, dated September 4, 1866, No. 57 ,823.

The disks A and 0, Figs. 2 and 3, together with the perforated ring F, Figs. 1 and 2, form a piston, having an annular hollow space, P, Figs. 1, 2, and 3. Into this hollow space steam is admitted, at each stroke of the piston, alternately through the openings 0 c, Fig. 2, and a, a, Figs. 1 and 2. Outside of the perforated ring F I place a compound expansible ring, consisting of the parts H and K K, the width of the expansible rings being slightly less than the ring F which supports the disks, as shown in Fig. 2. The object of making the rings H K K of less width than the inner ring F is to allow them freedom to expand under the pressure of steam. The inner ring F serves to form a bearing between the head A and follower O, and to keep them at the desired distance, leaving the outer compound ring H K K free to expand and revolve, so as to wear even] v.

The revolving of the outer rings is an observed fact whichI do not attempt to explain nevertheless it is an important feature in my invention.

The double-headed valve D is shown in Fi 3 and 4, and consists of a central part, I), and two smaller necks, R R. The necks are pro vided with grooves d d, and fit into valve open in gs, a, in the lower disk A, and c in the valveseat E, the valve being free to vibrate back and forth from its seat in G to its seat in A, admitting steam alternately.

To adjust this motion, I make the valve seat E adjustablethat is, its outer edge is provided with a screw-thread, which fits a corresponding thread in the disk 0, so that by simply turning E the motion of the valve 1) may be limited so as to admit just the desired amount of steam.

I claim as my invention The head A, follower (l, and fixed ring F, having steam-passages, as shown, in combination with the free-cut rings H K K, when the said rings are made free both from the disks A O, as shown and described, and from the fixed ring F, so that they may revolve, all substantially as described, and for the purpose set forth.

SAMUEL DAVIS KEEXE.

I Vitnesses:

FRANK Gr. PARKER, WILLIAM- EnsoN. 

